The short answer? Probably nothing to do with you and the fact that you did HAVE traffic goes to show that the content is optimized for those keywords, so don’t go changing the content if you don’t have real improvements to make.

Most popular sentence on the lens:

“Nobody ever asks why Google suddenly GAVE them a lot of traffic”

One reader notes that most of her traffic comes from forums, which she doesn’t count as significant. However, if it’s a public forum: the links from that forum TO her blog probably count as well for Google.

I also said:

As for keywords: I don’t bother with them for every lens I make, or every blogpost I write either. I do know however that I pay for that with less traffic than I’d otherwise have – paradoxically for most of my SEO lenses for instance.

I would recommend that when you blog about something you KNOW is likely to be popular, that in those cases at least you DO use keyword research on the title. Just write the rest the way you always do. It can make all the difference.